newlib-cygwin/libgloss/sparc_leon/kernel_sched.c

85 lines
2.6 KiB
C

/*
* Copyright (c) 2011 Aeroflex Gaisler
*
* BSD license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <asm-leon/contextswitch.h>
#include <asm-leon/leonbare_kernel.h>
#include <asm-leon/leonbare_debug.h>
#include <asm-leon/stack.h>
#include <asm-leon/leonstack.h>
#include <asm-leon/irq.h>
unsigned int
reschedule ()
{
leonbare_sched_update ();
return leonbare_sched ();
}
unsigned int
leonbare_sched ()
{
unsigned int ret = 0;
volatile leonbare_thread_t old = LEONBARE_KR_CURRENT, new =
LEONBARE_KR_NEXT;
LBDEBUG_FNCALL;
LBDEBUG_HEADER_PRINTF (LBDEBUG_SCHED_NR, "switch %s[%x]->%s[%x]\n",
LEONBARE_TH_NAME_DBG (old), old,
LEONBARE_TH_NAME_DBG (new), new);
LBPASSERT ((old != new),
"leonbare_sched should only be called with reschedule work to do",
0);
LEONBARE_KR_CURRENT = new;
/* to be able to programm symetrically on kernel level each thread
saves its spinlock on mutexes and kernel and irq flags in its
own save region. On a kernel switch they are released until the
thread is reawakened. Then the locks will be reaquired (and finally
released when the codeblock exits). The locking can be recursive. */
if (old->th_prot.krp_k_depth)
{
LEONBARE_SMP_SPINLOCK_RELEASE (LEONBARE_KR_LOCK);
}
if (old->th_prot.krp_m_depth)
{
LEONBARE_SMP_SPINLOCK_RELEASE (old->th_prot.krp_m);
}
ret = _leonbare_kernel_switchto (old, new);
optbarrier ();
if (new->th_prot.krp_m_depth)
{
LEONBARE_SMP_SPINLOCK_AQUIRE (new->th_prot.krp_m);
}
if (old->th_prot.krp_k_depth)
{
LEONBARE_SMP_SPINLOCK_AQUIRE (LEONBARE_KR_LOCK);
}
return ret;
}